Hydraulic press



June 2, 1931. w. E. MCCULLOUGH HYDRAULIC PRESS Filed April 1, 1929 2 Shets-Sheet l llllll IL Patented June 2, 1931 UNETED stares PATE tseaza r aue v WILLIAM HYDRAULIC PRESS Application filed April 1, 1929. Serial No. 351,590.

The present invention concerns a novel form of hydraulic press of the type used in plastic molding, die hobbing, and similar operations.

One of the objects of the invention is to provide a variable total pressure or lift press having a multiple plunger,-that is to say, having a plunger that is divided into a number of pressure-receiving portions, upon one or all of which portionspressure may be applied at will. 1

Another object ofthe invention is so to construct the hydraulic press that thesame may be closed comparatively rapidly by applying pressure to the main cylinder area of the plunger and thereupon additional power may be secured by applying additional pressure to a further portion of the said plunger, whereby the total surface area subjected to the hydraulic pressure of the high pressure water supply may be increased.

Another object of the invention is to so construct the hydraulic pressthat the re-.

verse movement or the downward movement of the cylinder may be accelerated by applying hydraulic pressure to the same instead 0 depending upon its weight as is usually the case, and to accomplish this without employing separate push-back cylinders.

A further object of the invention is so to construct a hydraulic press of the type hereinafter described as to allow ready access to the packing rings of the same, and also to enable repairs to be made thereto without the necessity of dismantling the press.

A still further object of the invention is so to construct a hydraulic press that different total pressures upon the platen of the same may be obtained by using any or all of the pressure chambers, one of said pressure chambers being in annular form.

Other objects of the invention will appear in. connection with the drawings and specification which form a part of thepresent ap'- plication, and in which drawings: V

Figure 1 is a vertical drawing, partly in section, showing the constructional details of the press insofar as necessary to explain the present invention; and j Fig. 2 is a top view of the press; and

Fig. 3 is a sectional view, along the line 33 of Fig. 1, lookingdownwardly in the direction of the arrows;

Fig.4 shows, in diagrammatic View, the top of a platen having a plurality of plungers attached thereto, this being a modification of my deviceconsidered to be a mechanical equivalentthereof.

As will be seen from Fig. 1, my improved hydraulic press consists of a foundation n. MGCULLOUGH, or xnnosna, WISCONSIN, ASSIGNOE To sitar/ions corr- PANY, or KE'NOSHA, WISCONSIN, A ooaroanzrron or DELA ARE v frame 10 which is, preferably, because ofv convenience of operation, placed in a wall 11 below the floor line 12 so that the platen 17 of the press will be at proper operating" height to allow. of convenientattendance by the operator. Upon this frame 10 there are erected steel uprights 13 which areattached to the foundation supports 10 by large nuts 14; At the upper'end of the supports 18 there is attached the head 15 which may be of the ordinary conventional design such as'is' commonly usedwith hydraulic presses. I This head 15 rests upon an off-setlfi located near the upper end ofthe upright supports13 and a is held fast thereto by means of the nuts 14a. Inslidable engagement with the uprights 13 is the platen 17, which, in turn, has mountedjupon it either rigidly attached or simply laid thereon a number of pressure bars 18 surmounted by a steel plate 19. Similar bars 18a and 19a are attached to the head 15 of the press. This part of the press equipment may be of the regular standardized construction and is therefore shown on'the drawings in conventionally diagrammatic form; The

hydraulic portions of the press consist of an outer water tight lower casing 20, in which a plunger or pressure head 21 is movable upwardly and downwardly, a water tightseal' between the walls of the casing 20 being provided and consisting of rubber or leather gaskets 22. These gaskets are annular in shape and lie within a suitable groove within the plunger head 21. The said gasket 22 is held in place by an annular ring 23 which is bolted into the plunger head 21 by means of the'bolts 24 and the nuts 25.

Attached to the plunger head 21 there is a cylindrical vertically disposed ram 26, the

latter being fastened to the plunger head by means of the cap screws 27. As an upper closure for the lower casing there 1s provided an annular transverse horizontally CllS- posed partition 27 which is bolted to an c nlargement at the upper end'of the casing 20' or rubber gasket 30 which is'held in place by an annular ring 31 fastened to the partition 27 by means of the bolt 32 and the nut 33.

As will be seen from Fig. 1 this provides an annular external chamber 34 whichis bounded on the outer periphery bythe casing 20 and on the inner periphery by the ram 26.

The casing 20 is completed on its lower sur face by a dome-shaped end piece 35 which is, preferably, cast as a single piece with the casing 20 as it must Withstand high hydraulic pressure. A11 inlet pipe 36 serves to supply water into thespace lt) between the plunger head 21 and the domeshaped end piece 35.

The ram 26 is elaborated "just beyond the transverse closure piece 27 into an internally hollow enlarged ram 26a which, m'turn, has the platen 17 of the press bolted to it by the bolts 37 and 3 8. I This upper portion 26a of the ram operates within a cylindrical casing 39 which is also bolted atitslower end to' the partition 27, a water tight seal'between' said partition-and casing 39 being assured by casing 39 is secured by means of the gaskets 41 which are held in place by the annular ring l2which is 'held to the casing 39by means of the bolt 43 and'the nut 14.

A water inlet 45 is provided in the wall of the casing'20 so that water maybe admitted to the annular space between the cas-' ing 20 and the ram 26. A similar water inlet 46 is provided in the wall of the casing 39 so that :watermay be admitted to the annular space 47 which exists between the enlarged portion 26a of the ram and the upper cylindrical casing 39 and the partition 27.

The platen'17 of the press is provided with laterally extending lugs 17a. The trans verse horizontally located partition 27 is also provided with similar laterally "extending lugs 27a, theselugs having bolt holes 17?) and 276, respectively, so that a connecting yoke 48 may be inserted'between thelugs 17a and 27a, suitable bolts being inserted intothe holes 17?) and 27?); In the ordinary opera tion of the press, these yokes 48 are not in place and their use will be described hereinbelow in discussing the mode of operation of my improved selective pressure hydraulic press. r

three water inlet pipes 36, 15 and 46, re-

spectively', although these valves are not shown as the press is-operated by remote control through a complicated system of iaes valves oluiwers andcams which form- 7 7 2D the subject matter of copending application Serial No. 357,736, filed April 24, 1929. 7 It is also to be'understoodthat the steel plate 19 surmounting the platen 17 serves to receive the dies or molds which serve to fashion the article that is-to be molded on the press.

These parts are not shown, as theyzare not essential to the present invention. It will-be noticedthat when the press is in anentirely open position, as illustrated in Fig. 1, that there is stillan appreciable space 49 between the dome-shaped end piece 35v and the plunger head 21.

The operation of my press is easilyunder-v stood. There is supplied to theipress, by means of suitable piping, two kinds of pres- I sure water, the first being designatedas low pressure water, being supplied at a pressure of about 80 lbs; to the square'inch, such as is usually available from city or private water supplies. The second supply of water is wa-- ter coming through suitably heavy piping "from an hydraulic pump and accumulator,

this water being at, say, 1,000 lbs. pressure per square inch. It is to be understood-that both p p high-pressure wateras well the low-pres a, preferably lead, gasket 40. A SllTlllELIf I water tight seal betweenthe' ram 26a and thesure water may be applied-threugh the inlets 3'3 and 46, although 1t is contemplatedthat only low-pressure water be admitted-tothe press through the inlet lVithout limit ing myself in any way to-the dimensions a given, letxit be assumeclfor the purpose. of.

the water admitted throughthe inlet 36 would xbe 25 4 square inches, which would correspond to an internal diameter of the casing 20 of 18;

inches. 'Then if the water pressure applied through the inlet 36 were at 1,000 lbs. per

square inch, this wouldcorrespond to a total pressure of 254,000 lbs. which would be communicatedthrough the rams 26 and 26a to the platen 17 of the press. In other words,i,in us- 7 ing only the lower water-inlet 36 andithe press will be 254,000 lbs. orl27 tons.

All of the presses known to me in the past merely have asingle water space and a single cylindricalram so that the pressure upon the press, that is to say, the total lift, can only be changed by changing the pressure of the higlrpressure Water. In accordance with my construction, however, I am able to gain selective pressures without necessitating changing .';the pressure ofthe high-pressure water-space49, the effective total lift of the water supply, and I accomplish this as follows: I may, for example, if a lower pressure is desired, merely apply high pressure water through the water inlet pipe 16 to the annular water space 17.. Let it be assumed, for example, that theinternal diameter of the casing 39 be the same as that of the casing 20, namely, 18 inches. Let it also be assumed, purely for illustrative purposes, that the diameter of the cut away lower portion of the ram 26a be 12 inches, thus leaving an annular space having a base corresponding to a ring 3 inches from inner to outer periphery. This would make an elfective area of 148 square inches against which the 1,000 lbs. per square inch of water pressure is applied. This would give a total lift, if water were only allowed to enter the annular space 47 through the inlet 46, of 148,000 lbs, or approximately 7e tons. It will thus be seen that the operator has a choice between a total lift of 127 tons or of 74- tons with the same source of high-pressure water. Now it is also possible to have water enter both the annular space 47 as well as the cylindrical space 49 through the inlets as and 36, respectively, as a result of which the total lilt will be equal to 74- plus 127 or 201 tons. Thus there is available to the operator of the press the ability to select any one of three pressures, depending upon the object to be obtained by the operation of the press, that is to say, he may use either the lower water space 49, giving a lift of 127 tons or the upper annular space 47 giving a lift r of 7 1- tons or both simultaneously.

-That, however, does not exhaust the possibilities of my improved press. For merely closing, and for low pressure holding, it is possible to use the ordinary 80 lbs. city or plant general pressure which would correspond to a lift on the low-er ram head 21, of just about 10 tons. If the ordinary water pressure of 80 lbs. be applied to the annular space 17 this would amount to about 6 tons; if the said low pressure is used in bothspaces 47 and 49 the combined lift would be about. 16 tons. By using the high pressure in one space and low pressure in another, intermediate values between those given may also be obtained, thus making the operation of the press extremely flexible and bringing out a result not hitherto attained.

When the press is to be open-ed after a pressing operation, the water pressure isreleased and leaves the press either through the inlets 46 and 36 or through entirely similar piping installed on the other side of the press diametrically opposite from the inlets but not shown as being .sulliciently illustrated by the inlet pipes 36 and 16. The press platen and ram will then sink under the influence of gravity pushing the water out from the annular space 47 and/or the space 49. This,

however, isia comparatively slow operation, and I may hasten the descentof the platen and ram by applying low pressure water to the opposite face of the plunger head 21 by letting water into the annular space 34:

through the inlet pipe 45.. This, it will-be noted, presents another possibihty'otvarying the pressure of the press for it is conceivable that one might apply high-pressure water to the annular space L7 while at the same time opposing the upper lift by applying low-pressure water through the pipe s5 3 so that the upward thrust per square inch will separate push-back cylinders is obviated and s the entire working mechanism of the press can be contained within the same space as the houslng 20 and the thereon superimposed housing 39. This is quite possible by providing the partition 27, thus allowingpressure to be applied to move the ram 26 in either direction. It is to beunderstood that there might be a number of partitions such as partition 27 and a number of chambers,

although I have only shown two in the" present application. The mere multiplication of suchchambers is to be. construed as coming w thin the scope of my present 7 invention. I

In order to enable an operator to control the press so that he may at all times be informed as to the exact pressures obtaining 1n the various pressure spaces, stutable gages installed in the piping are of course supplied,

but these, not forming a part of my invention, I :1;

are not shown. As already stated, I prefer to control my press by a control device described in copending application, Serial No. 357,736, April 24, 1929, which is so elaborated that the mere movement of a single lever throws into action'the various valves, gages, d1schar e valves etc. Various modifications of the press as shown may, of course,jbe made as the same is purely illustrative of the fundamental principle'ot the invention which consists in so constructing a press that variable litts will be obtainable with but one high-pressure water supply.

I will now describethe function of the yoke 48 which has been mentioned as being attachable to the lugs 17a 27a. The purpose of these lugs and the yoke is to allow the press to be partly disassembled so that repairs may be eiiectedto the various gaskets which keep the parts tight against the Water pressure, for instance, if it is desired to repair or have access to the gasket 22,

which is located in the plunger head 21 and. serves to seal the same against the casing Ordinarily this gasket is entirely inacc-essiup ble. 'lfrit :is desired to repair Tthis gasket,

tho iollowing procedure is followed. the bolts 28, holding the transverse partition" First,

27 to the enlarged head of the casing 20, are removed. ,Tlien'the yolrcs 48 are put into place, there being preferably fourof these,

two on each side otthe press. Pressure is then applied (low pressure) through the inlet pipe 36 intothevspace -19. The result of this will be that the rain 26fwillbe lifted,

and will push up the platen 17 and by reason lar construction shown.

' ply of the connection of the latter through the intermcdiation of the yokes &8 with the partition 2? will lift the latter also. Pressure -.is applied until the head of the bolt 2% is near enough to the surface of the now open casing 20, whereupon'the platen of thepress is blocked by suitable blocking means, such as cribbing, whereupon the water pressure may be released and the bolt removed and the packingrepaired, It will be noted that this also gives access to they gasket and its retainin means. Thus b. an extreniel' simple operation it becomes possible to disas semble the press by using its own pressure, something which to my knowledge has not been. possible before with presses constructed Y in accordance with'the prior art.

lVhilst I have showna single plunger having a'mainpressure-receiving head and an auxiliary annularpressure-receiving surface, i do not wish to be limited to the particu- It is to be. considered an equivalent of my invention to have a main"press-cylinder and plunger and also a number of auxiliary cylinders, all of which are in operative association with the platen of the press, so that by applying-pres sure to the auxiliary plungers the total effective lift of the press may be increased. Sim- 'ilarly by using'one or two. only of the auxiliary plungersthen the lift may be comparatively slight.

To. illustrate one of these equivalents, I

have, shown a diagrammatic top view of a platen in l. A main, centrally'located,

plunger 260inay be aiiixed to the platen'l'ZO,

detail, but a single high-pressure Water supis required. In actual practice, the dimensions herein given may be very widely departed-from and the press may be built very much larger with-' 'ut' departing from the fundamental prin ciple involved, namely, thatofthe selective pressure principle.

l/Vhat I desire to have protected by Letters Patent is:

1. In an hydraulic press, two casings, a

artition between said casin s V a ram ex- 7 V c a 7 tending through one of said casings and into the other pass ng through a suitable-opening in said partition, a pressure-receiving piston at the end of said rain within the second casing, said piston bein in sliding coiitacti with the Walls of said casing and making a Water-tight seal therewith, a main pressure-chamber at the end of said second chamber being confined by the end thereof and by the said piston, an annular waterspace betweensaid second casing and said ram being confined by the opposite. side of said'piston aiidthe Walls ofthe casing and the partition, said ram being enlarged to 'subst-antially'the size of the first casing for,

a distance substantially equal to the length of saidfirst casingbut to ming therewith an annular pressure-chamber bounded by said enlarged portions the part tion and the walls of the first casing, and means for-admitlllDgWVdtQl to said main pressure-chamber and said annular pressure-chamber and said water-space;

2. In an hydraulic press, vtwo casings superimposed upon each other, a partition between said casings, a ram passing through said partition, said ram being smaller than the one of said casings into which it extends but substantially of the same diameter of the other casing flOIll'WlllCll it extends, a pressure-receiving piston of substantially the same cross-sectional area as that of the first casing and fastened to'the endof said rain, a main pressurechamberat the end 01' said casing, an annular auxiliary pressure-chamher at the end of the other casing nearest the said partition, an annular water-space between the walls of said first casing and said. smaller portion of saidram bounded by said partition and the top of said piston, and means for admitting waterto said pressure-chambers and said water-space.

3. A selective. pressure hydraulic press comprising a casing closed at one end, a partition dividing said casing into two separate chambers, a rain having one end of lesser diameter than the other end so that a shoulder or oft-set is formed about midway thereof the wider portion of saidrain being in one of said chambers and the smaller portion in the other chamber, a pressure-resisting piston on the end of the smaller portion of said ram and forming with the end of the casing .a main pressure-chamber whilst the shoulder on said ram forms withthe said partition an annular auxiliary pressure-chamber, a

"third water-containing chamber being provided by the spacer bounded by the casing surroundingthe smaller portion of theram,

the rain itself, said partition and the reverse side of said piston; a platen: attached to the larger end of said ram, vertical supports for-guiding said platen, andmeans for ad;- amttmg and-exhausting water from said main pressure-chamber and said annular'auxiliary chamber.

4. A Variable-lift hydraulic press comprising a lower easing, an upper casing, a partition between said casings,laterally extending lugs on said partition, a ram in said casings, a platen supported by said ram, lugs on said platen, and means for connecting the lugs on said platen with those on said partition, whereby the. simultaneous movement of said partition and platen may be efiected by the operation of said ram.

In Witness whereof, I have hereunto subscribed my name.

WILLIAM E. MOCULLOUGH. 

